Hark! Three habitable planets found in our neighborhood

An artist's rendering of the Gliese 667 star system, which may have as many as three habitable planets, the European Southern Observatory said today.
European Southern Observatory

A team of scientists has discovered three potentially habitable planets in an area just beyond our solar system's back yard.

According to a press release by the European Southern Observatory (ESO) today, the astronomers found a group of six planets in the vicinity of a star known as Gliese 667C, at least three of which were termed "super-Earths" because conditions could support liquid water.

Located about 22 light-years away in the constellation of Scorpius, Gliese 667C is a star about a third the size of our sun, and is part of a triple-star system known as Gliese 667. Previous studies of the system had identified three planets, just one of which was thought to be potentially habitable. But the new study, conducted using the ESO's High Accuracy Radial velocity Planet Searcher (HARPS), a high-precision echelle spectrograph that was added to the ESO's 3.6-meter telescope at the La Silla Observatory in Chile, as well as data provided by the ESO's Very Large Telescope, the Magellan Telescopes, and the W.M. Keck Observatory, suggest that those earlier numbers were significantly short of the potential reality.

In its press release, the ESO said its scientists had confirmed that the three so-called super-Earths -- planets much larger than Earth -- are within the habitable zone of Gliese 667C. That zone is a thin shell around the star that has conditions that could allow the presence of liquid water.

The ESO said that although many compact star systems have been found in the Milky Way galaxy, the planets in those systems are usually uninhabitable due to intense heat from the nearby suns. But a star like Gliese 667C is cooler and dimmer, the agency said.